1. Field of the Invention
The present invention relates to a refrigerator, and more particularly, to an apparatus for controlling cold air circulation in a refrigerator, which allows the internal temperature throughout a refrigerating chamber of the refrigerator to be uniformly distributed.
2. Description of the Prior Art
FIG. 6 shows a sectional view of a refrigerator which employs a conventional apparatus for controlling cold air circulation therein. As shown in this figure, a freezing chamber 3 and a refrigerating chamber 5, which are-storage spaces formed in the interior of a main body 1 of the refrigerator, are separated from each other by a barrier 4. A plurality of shelves 5′ are installed at different levels in the refrigerating chamber 5 so that stored goods can be put on the shelves. A vegetable storage chamber 6 for separately storing fruits or vegetables therein is formed at a lowermost portion of the refrigerating chamber 5. In general, the vegetable storage chamber 6 is constructed in the form of a drawer.
The freezing chamber 3 and the refrigerating chamber 5 are opened and closed by doors 7, 7′, respectively, so as to communicate with the exterior thereof Inner surfaces of the doors 7, 7′ are provided with door baskets 8 for accommodating stored goods.
Meanwhile, an evaporator 9, which is one of constituent components of a heat exchange cycle for generating cold air to circulate in the refrigerator, is installed in the rear of the freezing chamber 3. A space in which the evaporator 9 is installed is shielded by a shroud 10. A grill fan 12 is mounted between the shroud 10 and the freezing chamber 3. Further, in order to circulate the cold air generated by the evaporator 9, a blower fan 14 is installed above the evaporator 9. The blower fan 14 causes the cold air to flow into a space between the shroud 10 and the grill fan 12. The grill fan 12 is also provided with a discharge port (not shown) through which the cold air is discharged to the freezing chamber 3.
Moreover, the cold air which has flowed downward through between the shroud 10 and the grill fan 12 is supplied to the refrigerating chamber 5 through the barrier 4. To this end, a refrigerating chamber duct 16 is installed in the rear of the refrigerating chamber 5 such that it extends lengthily from an upper end of the refrigerating chamber to a lower end thereof The refrigerating chamber duct 16 is formed with cold air discharge ports 17 through which the cold air is discharged to spaces partitioned by the shelves 5′.
Then, a freezing chamber return flow passage 18 is formed such that the freezing chamber 3 communicates with the space with the evaporator 9 installed therein through a top surface of the barrier 4 corresponding to a floor of the freezing chamber 3. The cold air which has circulated in the freezing chamber 3 is returned to the evaporator 9 through the freezing chamber return flow passage 18. Further, a refrigerating chamber return flow passage 19 is formed such that the refrigerating chamber 5 communicates with the space with the evaporator 9 installed therein through a bottom surface: of the barrier 4 corresponding to a ceiling of the refrigerating chamber 5.
However, there are the following problems in the conventional apparatus for controlling the cold air circulation constructed as such.
In the prior art, as a refrigeration cycle is operated and the blower fan 14 is also driven, the cold air which has circulated in the refrigerating chamber 5 is delivered through the refrigerating chamber return flow passage 19 to the evaporator 9 where heat exchange occurs, and then circulates in the refrigerator. Therefore, during the driving of the refrigeration cycle, the temperature of the refrigerating chamber 5 is relatively lowered since a great deal of cold air is delivered to the refrigerating chamber 5. On the contrary, when the refrigeration cycle is stopped, the temperature of the refrigerating chamber 5 is rapidly increased in a state where there is no cold air flow. In such a way, if the cold air flow varies depending on the turning-on/off of the refrigeration cycle, the temperature deviation in the refrigerating chamber 5 becomes larger. Consequently, freshness of the stored goods is deteriorated.
Particularly, the cold air supplied to the refrigerating chamber 5 through the refrigerating chamber duct 16 is relatively less influenced by the blower fan 14. Further, the cold air is relatively less delivered to the door baskets 8 spaced far apart from the discharge port 17. Thus, the temperatures of the door baskets 8 are relatively higher than those in the shelves 5′ located at the same levels as the baskets 8. Such a phenomenon becomes severest at a position corresponding to the position of the vegetable storage chamber 6, which is a position of the lowermost one of the door baskets 8.
Moreover, an actual temperature of the vegetable storage chamber 6 is relatively higher than an optimum temperature therein. This is because there is a relatively little amount of cold air which flows toward a lower portion of the refrigerating chamber duct 16 and is then delivered to the vegetable storage chamber 6. That is, according to the prior art, the cold air is not uniformly delivered to the entire refrigerating chamber 5. Thus, it is likely that the temperature of a lower portion of the refrigerating chamber 5 becomes relatively higher, whereas the temperature of an upper portion of the refrigerating chamber 5 becomes relatively lower.
Thus, there are disadvantages as described below. Since the temperature of the refrigerating chamber 5 is not uniformly set in such a way, the freshness of foodstuffs stored in the lower portion of the refrigerating chamber 5 is deteriorated. In addition since the cold air in the upper,portion of the refrigerating chamber 5 is returned to the evaporator 9 in a state where the cold air is at a relatively lower temperature, heat loss occurs in the evaporator 9.